Are you getting an Auto or a manual?
I don't want to start any arguments here either with regards to Tuners, but I have gotten Xcede software for my 2004 E46 330d and the difference is night and day, I went from 114kw ATW and 372nm to a 167kw ATW and 564nm Torqu!! I then went for a further tweak on the software and the car is now an absolute monster, Now its definitely pushing over 600nm of torque, I have not dynoed it yet but from the first time the software was done to the second time the power difference is something else.
The most important thing is that it has been very reliable so far, no engine lights coming on etc etc, no surging, just very smooth power delivery. I had the software done last year, not sure when exactly but its been a while.
I am very keen to do all the little tweaks that Andy has done to his car like the engine mounts and vacuum hoses etc as that stuff apparently robs a substantial amount of power, Just need to find the time.